Treatment of material in a vacuum and apparatus



Au'g. 10 1926. 1,595,489

- A o. MINToN TREATMENT oF MATERIAL 1N A VACUUM AND APPARATUS original Filed Maron A. 1920 zsneets-sheet 1 I'VVENTOR,

BY MQW ATTORNEY Aug. 10 1926. 1,595,489

o. MlNToN TREATMENT 0F MATERIAL IN A VACUUM AND APPARATUS Original Filed March 4. 1920 Z'Sheets-Sheet 2 z 'IWENTOR @gm ATTORNEY Patented Aug. 10, 1926.

. UNITED STATES 1,595,489 PATENT OFFICE.

OGDEN MINTON, OF GREENWICH, CONNECTICUT.

TREATMENT OF MATERIAL IN A VACUUM AND APPARATUS.

Original application iled Marchri, 1920, Serial No. 363,350. Divided and this application led larok 20, 1922, Serial N0. 545,216.

This application is a division of my copending application Treatment of mate; rial in a vacuum and apparatus, iiled March 4, 1920, ser. No.36a350, Case' F.

The present invention relates to an apparatus and method for the drying of paper and other material, as sheet material, and immediately coating, or coloring, or sizing or impregnating it while still in the vacuum chamber.

My improved method consists in passing vthe material which is to be dried into a vacuum chamber through a liquid sealing medium which has no affinity for the material, subjecting it to heat to drive off its contained moisture, immediately coating or coloring, or sizing or impregnating the material while in the vacuum chamber, and then passing .the material out of the chamber through a seal.

This method may be practiced by the use of various forms of apparatus, some of which are herein disclosed. In any form, however, it is essential thatthe apparatus be provided witha closed chamber 1n which a partial Vacuum may be maintained. In order that the material to be dried and treated may be continuously passed through the vacuum chamber, the latter is provided with openings closed to the admission of air by a liquid sealing medium which has no aflinity for the material. The liquid seal effectively closes the entrance and exit passages against the admission of air to the chamber, but permits the passa e of the material into and out of the cham er.

My invention further relates to obtaining a better and more uniform product than any now known on the market. M further relates to the method o coating or impregnating sheet material which insures that there will be no blemishes, uneven surfaces, blisters or minute raised portions due to the air `which may be held or occluded within the sheet material, which in the present practice of coating as for example with a water-proof compound, leads to rejections or discards due to these imperfections with the consequent waste of material andl labor.

My invention further relates to the treatment of paper'and drying it in a vacuum chamber, and coating or impregnating it or coloring it therein without breaking the vacuum. My invention further relates toperforming these steps continuously on a invention Renewed February 17, 1926.

continuous web of paper. This web of pa per `may be fed direct from the wet end of a paper machine, or the web may be first p wound into a roll or reel as may be found convenient or expedient. y

My invention further relates to manufacturing paper wherein the fibers are not weakened and the size in the paper is not inj ured or damaged due to drying at high temperatures.

My invention further relates to manufacturing colored paper and drying it without substantially impairing the coloring matter and mordants used in the pa er. Among other advantages this insures t at the paper will have bri ht colors, which will be susstantially uni orm in different runs of paper, permitting matching of colored paper without any appreciable dierence in tone or color.

My invention further relates to rapidly and expeditiously coating or impregnating sheet material in a continuous web or sheet.

My invention further relates to sizing paper in a vacuum chamber at such low temperatures as not to injure the fibers of the paper or the size. My invention further relates to withdrawing the occluded air from the paper and immediately drying and then filling the interstices normally filled with the occluded air with the size. My invention `further relates to carrying out this method ber without breaking the vacuum.

My invention further relates to certain steps, and combinations of steps, also to certain elements and combinations of elements, whereby the method or processes herein described may be carried out, as well as to certain details of construction, all of which will be 4more fullyhereinafter described in the specification and pointed out in the claims.

The accompanying drawings, which are partly diagrammatic, illustrate several, but

los

' impregnating material, or

not the only, forms of my apparatus, by the use of which my im roved method may be practiced.' In these rawings the same reference numerals refer to simllar parts in the several f1 ures. y

Fig. 1 1s a diagrammatic vertical section of one form of. apparatus Fig. 2 is a vertical diagrammatic section of a modified form of apparatus in which a combination of heated drums or cylinders and a heated bath are used to dry"and finish the sheet material;

Fig. 3 is a vertical diagrammatic section of another modification in which diiferent drums or cylinders of different size from those in Fig. 2, are used with a heated liquid bath to vary the finish given to the sheet material.

In describing my invention I will describe it as applied to sheet material in the form of paper though it is to be distinctly understood that textile fabrics may also be treated by my process and that my broader claims cover all forms of materials.

In the ordinary drying of a web of paper such high heat is used as to injuriously affect the fibers of the paper; and in case the paper is colored it will'materially affect the coloring matter and mordants used.

Drying paper in the high temperatures used in ordinary practice often alects the size so that the resulting paper varles in quality, is not uniform and is not a perfect product.

In coating or impregnating fabrics it is found in practice that the coated fabric will frequently have blemishes due to large or small blisters and blow holes, these often being about the size vof a pin-head or pinpoint. This is caused by the air which is heldv or occluded being collected, more or less, in small pockets under the coating or 1n some cases causing minute blow holes. In water proof .fabrics this results in large quantities of the material being rejected with the conse-.I

quent loss to the manufacturer.

By my invention I insure that substantially all the occluded air is withdrawn from the sheet material which will permit the coating or impregnating material, whatever it may be, to thoroughly fill these minute interstices or pockets normally occupied by occludedI air, forming thereby a better and more uniform product and one devoid of blisters, blow holes or such blemishes.

The web 1 of paper may be fed direct from the wet end of a paper machine, the

v. j vacuum chamber A being properly positioned adjacent to such paper machine. Or, the web 1 may be fed, from a roll or reel 3 of wet or damp paper over the guide roller 4 and into the liquid seal 5. This seal may be of any suitable medium which has no alinity for or deleterious eiect upon the sheet material treated. I preferably use a liquid seal ofmercury, though it is to be distinctly understood, that any amalgam, alloy, or any other suitable liquid sealing medium may be employed which has the characteristics above specified. The web 1 is fed down through this liquid seal under the roller 6 and then up into the vacuumv chamber 2 in contact with the guide roller 7, and thence through the heated bath 8 under the submerging rolls 9, 9 and over the guide rolls 10, 10 to the guide roll 11 by which time it is thoroughly dry. It then passes, while still in the vacuum chamber, through. the coating, coloring, sizing or impregnatlng bath 12 under the submerging roll 13, between the squeeze rolls 14, 14 and over the guide rolls 15, 15, thenceunder the submerging roll 16 in the second seal 5',

and out through said seal over the guide roll 17, where it can be rolled into the roll or reel 18.

The heated bath 8 is of any medium which has no aflinity foi or deleterious effect upon the material treated. This liquid bath may be, and preferably is, heated mercury, though it may be any suitable amalgam, analloy or any other suitable medium .which has the characteristics above -spec1iied. This bath may be heated in any iitsgle manner such as by the steam pipes The Vacuum chamber A is provided with the pipes 20, 20 connected toxby'suitable vacuum apparatus. I also provide the vacuum chamber with windows` 21, 21 s that the operator can at all times watch the drying of the material within the chamber. The metal of the bath may b e supplemented from time to time by means of the cock 22. This cock can a-lso be used to drain the chamber 23 when it is desired to clean it. The metal of the bath 12 may be heated by the steam pipes '24.

In some cases it may be desirable to give the coated or impregnated material 1 a different nish from what it would receive in the apparatus shown in Fig. 1. I may for example pass the web 1, Fig. 2, into a vacuum chamber A, and then through a liquid heating bath 8 having the. characteristics above mentioned. In passing the web 1 through this heating bath 8, I employ drums or cylinders 25, 25` which may be heated or not and which are partially submerged in the bath. These drums may be rotated if desired in any suitable manner.

The web l passing through the vacuum chamber A in contact with these drums 25, 25 and also over the guide. rolls 26, 26 is thoroughly dried and then passes over the guide roll 27 and into the coating or impregnating bath 12, and out through the squeeze rolls 14, 14 and the second liquid seal 5 in the manner previously described masas@ in connection with the other forms. The liquid bath 8 may be heated in any suitable manner such as by passing steam, hot water, or products of combustion through the chamber 28. y

The finish and smoothness of the web 1 may be still further varied by changingthe' size of the rolls 25, 25. These changes may be made within Wide limits. Simply for purpose of illustration I have shown in Fig. 3, a vacuum chamber A in which the same heating bath 8 is employed but instead of the drums 25, 25 I employ drumsv29, 29 Which are considerably smaller in dia-meter. In this modification the web 1, particularly if it is of paper, Will not have quite so iat and smooth a finish as it would have by employing the apparatus of'FiO. 2, but it will have a smoother and iiatter hnish than that given by the ap-paratus of Fig. 1. While these diierent forms are shown it is of course to be understood that they are simply illustrative-and that my invention is not to be confined to them. The finish will also depend somewhat on the depth to which the web 1 is caused to penetrate the heated liquid bath 8. The deeper it is forced into the bath the greater will be. the pressure of theliquid upon the Web. A

The web is thoroughly dried in this manner while in the vacuum chamber. Substantially all its occluded air is also Withdrawn and passes ofi' with the steam and other vapor through the pipes 20, 20 to any suitable \form of condenser or vacuum apparatus (not shown). Vhile still in the vacuum chamber 2 and While dry I immediately subject the webv 1, Whether it be paper or textile material, to some suitable coating or sizfng, imp-regnating or coloring material in the chamber 23 in the form of a bath 12. This coating or impregnating or coloring material may be of any suitablematerial with which 1t is desired to coat or impregnate or color the Web 1.l For example., it

may be size,l Wax, tar or infact any coating or waterprooiing or impregnating or coloring material. v

p The web 1 passing into said coating or iinpregnating bath 12 dry, and with its interstices devoid of practically all occluded air will immediately become coated or impregnated with portions of said bath as itJ passes under the submerging roller 13 and out between the squeeze rollers 14, 14, which remove ali the surplus coating or impregnating material. The amount of the coatingor impregnating material taken up by the Web 1 will depend somewhat upon the speed with which the web is fed thro-ugh the vacuum chamber, but it is to be understoodthat my machine is a high speed machine. The web will then pass over thel guide rolls 1.5, 15 and down into the second liquid seal 5 unf der the roll 16. This liquid seal 5 is preferably of the same material as the first 1iq uid seal 5, though of course it need not necessarily be, but it must not have any afiinity for or deleterious action upon the coated or impregnated Web 1. Theweb is then fed over the guide roll 17' and is preferably' rolled '1n the roll or reel 18, though it may be cut or stacked or further treated, as may be found convenient or expedient.

'Ihe thermal elicieney of my vacuum method is very much greater than that of the atmospheric cylinder drying hereto-'fore in universal use for drying paper. Theoretically, it requires about 5287 pounds of steam to dry one ton of paper at atmospheric pressure, but to compensate for ,convection and conduction losses, and those due to leaks in the piping system, and other ineiiciencies, it has been shown in practice that about 10,600 `pounds are required.

ln my method, using a vacuum of about 28, the convection, conduction and piping losses are exceedingly small and the total steam required Hto dry a ton of paper by my methodis approximately 5200 pounds.

It is an established 'fact that paper dried at low temperatures lis much stronger than when it is dried at the high temperatures used invp-aper machine atmospheric drying. Paper ried in a vacuum of 28, or at a temperature of about 100O F., as in my method, is very much stronger than paper dried at atmospheric pressure, when the steam in the driers is at 228o F. When paper is dried by my method, therefore, a cheaper furnish can be used and still produce a coated or sized paper equal in strength to atmospheric driedpaper, in which a higher print paper, I Vam able to dispense With'a considerable portion of the more expensive v sulphitepulp, as this can be *replaced with the cheaper ground wood pulp. By my method I yalso reduce the number of breaks in the Web as it passe-s over the'cylinder. Nor will the size or coloring matter and mor dants, if any be used, be injuriously eected.

Furthermore, in my method there is a great saving of heat (or steam) because the process is carried o n in a vacuum chamber which acts on the principle of a thermos bottle, and the, steam and vapors driven out of the Wet paper are caught in the closed vacuum chamber, and conducted away to the condenser. steam, humidity and heat, and fans, and exhausters are dispensed with. In the use of my method the apparatus is at all times operating under definite humidity, the control of the drying can be closely standardized, and the moisture content in the paper ca-refully regulated.

Having pointed out the manyv advantages The Loperating room is free from of my method and apparatus over those use of my invention results in great economy in the initial cost of apparatus and in large savings in cost of operation, maintenance and repairs..

Having thus described this invention in connection with illustrative embodiments thereof, to the details of which I do not desire to be limited, what is claimed as new and what is desired "to secure by Letters Patent is set forth inthe appended claims.

1. The method of treating a web of Wet paper consisting in feeding it continuously into and out' of a vacuum chamber Without breaking the vacuum, drying said web of paper in the vacuum chamberl by contact with a liquid heated bath and drying drums or cylinders,` and then continuously coating or impregnating the web vin the vvacuum chamber before permitting it to reach 'the atmosphere. l

2. The method, of treating a web of Wet v paper consisting 1n feeding it continuously:

into and out of a vacuum chamber without breaking` the vacuum, drying said Web of paper in the vacuum chamber by permitting its fibers to be acted upon by liquid and solid drying elements to Vary the linish of said paper, and then continuously coating or impregnating the web in the vacuum chamber before permitting it to reach the atmosphere. s 1

3. An apparatus for continuously treating Wet material including a vacuum chamber, means to permit the Wet material to pass continuously into said vacuum chamber Without breaking the vacuum, drying means mounted near the entrance to the Vacuum chamber including a heated bath and means mounted in the bath to exert a predetermined degree of tension upon the fibers, of the material to give the particular finish, smoothness or flatness desired, said bath having no affinity for or deleterious affect uponv said material, coating, sizing or impregnating means mounted in the vactinuously into said vacuum chamber Without .g

breaking the vacuum, drying means mounted near the entrance to the vacuum chamber including a heated bath and means mounted in the Vbath to exert a predetermined degree of tension upon the ibers of the paper to give the particular finish, smoothness or iatness desired, said bath having no alinity for or deleterious eii'ect upon said paper, coating, sizing or impregnating means mounted in the vacuum chamber adapted to continuously coat, size or impregnate the dry paper, and means to permit -the coated, sized 'or impregnated material to pass continuously from the vacuum chamber Without breaking the vacuum.

5. An apparatus for continuously treating .Wet material including a vacuum chamber, means to permit the Wet material to ass continuously into said vacuum chamser Without breaking the vacuum, drying means mounted near the entrance to the vacuum chamber including a heated bath and rolls of the required diameters mounted in the heated bath to exert a predetermined degree of tension upon the fibers of the material to give the particular finish, smoothness, or flatness desired, said bath having no affinity for or deleterious affect upon said material, coating, sizing or impregnating means mounted in the vacuum chamber adapted to continuously coat, size or impregnate the dry material, and means to permit the coated, sized or impregnated material to pass continuously from the vacuum chamber without breaking the vacuum.

OGDEN MINTON. 

